The invention relates generally to interior lighting for residences, businesses and other locations, and, in particular, to fluorescent lighting.
The 1990's have seen a renewed national commitment to saving energy. However, in many areas residential lighting energy conservation efforts have not generally delivered their full potential. While most end use areas have seen 30 to 50 percent efficiency improvements, numerous resources remain unmined. Moreover, lighting efficiency has been, in places, clumsily implemented and consequently, has not been well received by consumers. Residential lighting in particular, is a microcosm of these larger trends.
Each year in the U.S. about 145 billion kilowatt-hours of energy are used to light homes, at a cost of 10 billion dollars, and resulting in the emission of approximately 140 million tons of carbon dioxide. Promoting and installing more efficient residential light sources, fixtures, and controls can significantly reduce these numbers. The compact fluorescent lamp (CFL) is the most dramatic example of such a technology, offering a 75 percent increase in total lamp lumens per watt over the ubiquitous general service incandescent lamp (A-lamp). Unfortunately, actual applications of CFLs often fail to deliver on promises of equivalent light quality, quantity, and distribution, at comparable cost to traditional lighting.
One of the most popular residential lighting fixtures is the table lamp fixture. These use almost exclusively 60-100 watt incandescent lamps. But they do not offer distribution control.
The current perceptions of CFL table lamps are that they are expensive, not bright enough, prone to failure, and don't look good. This results in widespread consumer rejection. Thus, of the large potential market for residential table lamps, 90 million homes with three plus table lamps per home, CFLs have attained only about 1 percent market share or less.
Of all CFL table lamps, most are screw-based retrofits (Edison sockets); almost none are pin-based hardwired fixtures. Most common are lamps with single, vertically oriented CFLs, e.g. 9-40 watt twin, quad and multi-tube configurations. Some of these are encapsulated in a plastic capsule or globe. The vertical orientation is inefficient in that it directs flux towards the shade. Single lamps offer no control of light distribution out of the fixture. Single planar CFL lamps, e.g. circline and 2D CFLs, are better inside shaded table lamp fixtures, but control is only available through level/intensity control with electronic ballasts.
There is a commercial hardwired table lamp configuration using three twin-tube CFLs arranged radially in a vertical orientation. Switching one, two, and three lamps offers three level intensity control, but there is no control over light distribution.
Multi-lamp incandescent table and floor lamps have traditionally offered level intensity control, typically in dual or triple lamp configurations, usually arranged radially around the center, or with three level switching and/or dimming of a single lamp, e.g. a 50-100-150 W A-lamp. However, control over distribution of light out of the fixture into the room has not generally been provided.
A significant feature of a new lighting fixture based on any type of lamp would be control of light distribution out of the lamp, i.e. the user can readily select and vary the light distribution to meet changing needs. For example, under some conditions direct lighting is needed, while under other conditions indirect lighting is desired. Thus a light fixture which allows a user to readily switch between direct lighting, indirect lighting, or both, would be highly advantageous since the lamp would deliver most of the light where it is needed. Coupled with efficient light sources, e.g. CFLs, tremendous lighting efficiency can be achieved. Unfortunately, present lamps are generally configured with a fixed light output distribution pattern which cannot be changed by the user.
Therefore, it is desirable to provide new lamp fixture configurations for CFL based lamps which take advantage of the great advances in CFL technology made in recent years and which allow easy selection and control of light distribution. High quality phosphors and electronic ballasts produced in the 1990's and the many new shapes, sizes, and colors available provide a lot of flexibility in lighting options. However, the integration of CFLs into table lamps has primarily involved trying to make CFLs behave like incandescent lamps instead of taking advantage of the inherent characteristics of the CFLs. The new design should have high performance, flexibility in control, and provide lots of light for user amenities. A new CFL table lamp fixture design with these features could capture a significant market share. At present, with 90 million homes having three plus table lamps per home at a cost of about $75.00 plus per fixture, with a present CFL market share of less than one percent, there is huge potential for market growth with an efficient CFL fixture. The market potential is further expanded when the lighting system design is applied to table lamps for offices, hotels and other locations, and floor lamps for all these locations.